Conventionally, as a liquid droplet ejection apparatus, an apparatus including a channel having a volume to be changed by a pressure generation element and a nozzle communicating with the channel has been proposed (Patent Literature 1).
In this liquid droplet ejection apparatus, when the volume of the channel is reduced by the pressure generation element, a liquid filled in the channel is ejected outward as a droplet through the nozzle. This liquid droplet is dropped onto a recording medium to form an image on the recording medium.
The viscosity of a liquid used in this liquid droplet ejection apparatus is 8 millipascal second or more. The nozzle has a first portion (funnel portion) defining a truncated conical space having a taper angle of 40 degrees or more on a side of a channel and a second portion having a shape (cylindrical shape) in which the cross-sectional area is substantially unchanged on a plane orthogonal to a nozzle direction on an ejection side.